Jobo 2509N reel problem

[younghoon Kil]

Hello,
I use a 2520 tank and 2509N reel to develop film with minimal agitation. I often use B's Processor as well.
However, I get several marks on the edges of the film as shown in the attached photo.
I believe these marks are related to the protrusions in the guide rails of the 2509N reel, but I don't know how to fix this.
If you have a solution to this problem, please advise.
Thanks.

[Lachlan 717]

Do you use the paddles?

[Graham Patterson]

And you do load with the emulsion side towards the core?
Since this is 'minimal' agitation you are manually inverting a full tank?

[Lars Holte]

And you do load with the emulsion side towards the core?
Since this is 'minimal' agitation you are manually inverting a full tank?

This is good advice: the emulsion side should face the core. This will take care of the marks near the two corners. And the tank should be rotated on rollers and filled with a relatively small amount of chemicals - 270 ml in the case of 6 sheets of 4x5.

[younghoon Kil]

Do you use the paddles?

Yes!

And you do load with the emulsion side towards the core?
Since this is 'minimal' agitation you are manually inverting a full tank?

Yes!
I fill the tank with 1,400 mL solution, continuous agitation for the first minute, then 5 seconds every 3 minutes.

Anyway, even when using B's Processor, I get these marks on the edges of the films.
Thank you all for your responses!

[Lachlan 717]

Do you prewash?

[Vaughan]

I fill the tank with 1,400 mL solution, continuous agitation for the first minute, then 5 seconds every 3 minutes.

Insufficient agitation. Large sheets will suffer bromide drag, good agitation is necessary. The 2520 tank needs 1500ml for inversion agitation, you are under-filling.

I have the same reel and JOBO 2520 tank (as well as a larger 2550 tank) I suffered from uneven development when using it for inversion agitation. I really wanted inversion to work, I'd been using it for 35mm and 120 for years. I determined that the main causes were the long fill time (around 15 seconds, 20 seconds for the large tank) and developer was dribbling onto the sheets while filling when the chemicals overflow the light baffle.

My method now is:

0) Handle the film with gloves, never bare hands.
1) Use continuous rotary agitation not inversion. A manual base is perfectly good however I recently splurged and got a motorised base: the results are the same.
2) Use the minimal amount of chemistry taking into account the number of sheets and dilution (I use HC-110 or the Ilford equivalent almost exclusively).
3) Reduce the fill time and minimise spill onto the sheets. Get a funnel that fits snuggly into the central core of the tank top, and pour the chemistry through that. Be quick but don't overflow the funnel, make sure all chemistry goes through the core to the bottom of the tank without splashing over the top onto the sheets. It should take only 5 seconds to pour 500ml, get the lid on and have the tank on its side rolling.
4) Use developing times longer then 5 minutes, preferably 7 minutes or more. Mine are typically 10 minutes.

[younghoon Kil]

Do you prewash?

Yes. 3 minutes.

[younghoon Kil]

I never thought that 1,400 mL solution would be insufficient.
Next, I'll try 1,500mL.




I use a home made processing rig to develop my 4x5 films.




But I like the look and feel of minimal agitation.
Anyway, both inversion agitation(1,400 mL, 30 minutes) and rotary(500 mL, 8 minutes) make these marks.
Thanks for your advice.

[Lachlan 717]

I never thought that 1,400 mL solution would be insufficient.
Next, I'll try 1,500mL.

Just take the lid off, put in the reel, fill so that the top of the reel is covered by 5-10mm of water and then decant into a measuring cylinder.

No need for trial and error with volume…

What developer are you using? Is it HC-100?